| 摘要 |
PURPOSE:To enable to regeneratively brake uniformly irrespective of a motor rotating range by reducing a motor current at regenerative time at high speed rotation time of an AC motor, thereby preventing the excess torque of the motor from generating. CONSTITUTION:The regenerative current of a 3-phase induction motor 10 is supplied to a battery 14 at regenerative brake time. The detection pulse of a rotation detector 26 is converted by a frequency/voltage converter 101 into a voltage, input to a comparator 103, and compared with a reference voltage. When the output of the converter 101 exceeds the reference voltage, a comprison signal is output to an AND circuit 105. A signal representing that the motor 10 is regenerative is supplied from a converter 46 to the AND circuit 105. The output of said circuit is supplied to a triangular wave amplitude controller 107, the output amplitude of a PWM carriage triangular wave oscillator 28 is controlled to reduce the duty ratio of a motor applying voltage by the PWM comparator 36. |
